Election Night Webcasting Statistics On Election night, 2005, CityLink/R2 was involved in assisting a number of broadcasters with their streaming requirements. This was in addition to the normal webcasting activites being carried out with other TV and radio stations. Particular focus was placed on TV-One (TVNZ) TV-3 NewstalkZB National Radio The streaming was carried out using servers located in Auckland, Wellington and Palo Alto (USA). Encoding was carried out by TVNZ and CityLink/R2. In terms of number of viewers, the 2003 Lord of the Rings premiere has been regarded as the biggest event webcast to date. The election night figures passed that by approximately 50%. On election night, some servers used anycast routing to spread traffic between servers, so that viewers connected to the server closest to them by Internet topology. Because not all servers used anycasting, we experienced congestion on the link feeding the US based server. As a result, some viewers used the link to NZ servers, further overloading the International capacity. In hindsight, we should have fed the US server via an alternate route to ensure the quality of its streams. In terms of traffic, the average bandwidth being consumed was Auckland (2 servers) = 110 Mbps Wellington (1 server) = 50 Mbps USA (1 server) = 50 Mbps Total average bandwidth = 210 Mbps Peaks were of course much higher. Estimates are that approximately 450Gbytes of data was transferred during the event of 6 hours. 98% of this data was carried by the anycast routing architecture. At 10 cents per megabyte this data represents approximately $45,000. CityLink delivered this event for free as a public service. Lessons Learned Our experience suggests that for large events, anycast routing delivers high performance. However, the source feed to the US servers needs to be isolated from any other traffic into or out of NZ. We could have done this using our satellite capacity or by strictly enforcing anycast routing. This would have meant that NZ ISPs not peering at NZ Internet exchanges would have to bring significant traffic into NZ on their International circuits.
participants (1)
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Richard Naylor